The major functions of the Study Design and Clinical Research Core are to (1) assist clinical and basic science investigators in digestive diseases with appropriate study design, statistical analyses, and data interpretation, and (2) assist these investigators in acquiring clinical specimens required for their digestive disease-related research. This Core has been highly productive and beneficial for members of the TMC Digestive Diseases Center. In the last 4 years, 22 Full Members used this Core as did 20 Associate members and Pilot and Feasibility (P/F) Awardees. Major Core services include providing study-design and statistical-analysis support; establishing procedures for data management and database organization to facilitate efficient analyses; assisting DDC investigators in acquiring clinical specimens needed for their research; assisting and training in compliance, patient confidentiality and oversight issues, including preparation of IRB requests and preparation of Investigational New Drug (IND) applications; and educating members via meetings and seminars. Each of the three Core Co-Directors brings a unique area of expertise in clinical and translational research, namely sample and tissue collection, epidemiology and health services research, and biostatistics. The three Core Co-Directors have a strong track record of collaborative work with investigators at the DDC, The UT-School of Public Health, Health Services Research Section at BCM, and The University of Texas M.D. Anderson Cancer Center. Advances during the past 4 years include the expansion of sample and tissue collection and banking, and the increased number of requests involving epidemiology and health outcomes research, especially those using electronic databases to capture large amounts of patient information, risk factors, therapies, and outcomes; these databases include large disease registries and healthcare claims data. The Clinical Core has been critically involved in developing the new human organoid (within the Integrative Biology Core) and microbiome services at the DDC. We anticipate the growth of demand for biological sample collections from basic and translational DDC investigators due to the increase in research using the Integrative Biology for organoid cultures and Microbiome Core. We also anticipate the growth of demand for expertise related to health services research in digestive diseases from newly recruited investigators and the newly funded T-32 NIDDK training program in epidemiology and outcomes of Gl diseases.